I'm thinking of buying this airstream, but I don't know if my truck can handle it, also does it have elec. brakes? I have a 1/2 ton v8 truck bumper mount ball.
The '68 Ambassador would have had the rather typical electric drum brakes of the period with a breakaway switch on the hitch that will likely need service if the ones on my '78 Argosy and '64 Overlander are an indication (both needed to be replaced before first towing expedition).
There are several reasons why you would be well-served to have a receiver hitch with a properly adjusted ball mount installed on your pickup.
1.) If you pickup is anything like the '95 Chevrolet K1500 that I once used to tow my Overlander, the bumper mounted ball would be at least 5" too high for the trailer resulting in a nose-high towing attitude that could prove disasterous for handling on the highway.
2.) Depending upon how your tuck was optioned initially, the weight of the hitch "could" take enough weight off of the front wheels to produce some undesirable steering control characteristics. Weight distribution bars are beneficial even when there is minimal compression of the tow vehicle's rear suspension - - I always use the weight distribution bars even when I tow my 3,200 pound Minuet with the K2500 Suburban.
3.) A properly adjusted hitch would also lessen the chance of damaging any of the running gear components on the trailer due to placing too much load on one axle or the other from an other than level towing stance.
Even empty, you won't regret having the brakes operable. I only towed my Overlander once for a very short distance with the brakes on one axle non-operational. It was a VERY serious control issue with the 1/2 ton pickup to take up the braking slack - - this was in light city traffic for approximately 35 miles. With both of my coaches, the biggest obstacle to getting the brakes functional was rewiring the umbilical connector that was still wired to the period Airstream pattern which, of course, isn't compatible with the newer standard that most current tow vehicles have for their wiring.
Good luck with your proposed acquisition!
PS: Murphy of Murphy's Law fame is my constant traveling companion, so I always err on the side of conservatism when it comes to towing issues. I have actually encountered, on two different ocassions in the past ten years, vehicle inspection roadblocks where every vehicle on the highway was being stopped and inspected for required safety equippment - - this applied to both the tow vehicle and trailer. In both cases, the inspection was purely visual so they didn't actually test the operation of the breakaway switch - - but they did have me demonstrate that all of the signal lights were functional and that there was a brake controller installed in the tow vehicle. They also checked to be sure that the safety chanis were properly crossed and of "acceptable" length.